Bollinger Bands %W

Bollinger Bands %W (also written as %B) is a derivative of the classic Bollinger Bands indicator that normalizes the position of the current closing price relative to the upper and lower bands. It is calculated as: ((Current Close − Lower Band) / (Upper Band − Lower Band)) × 100. This formula transforms the raw band values into a percentage scale, where a reading of 100 means the price is at the upper band, a reading of 0 means it is at the lower band, and a reading of 50 indicates the price is at the middle band (the moving average). Values above 100 or below 0 indicate the price has moved outside the bands entirely.

The %W indicator makes it straightforward to identify overbought and oversold conditions. Readings above 80 are generally considered overbought, suggesting the price may be overextended to the upside and due for a pullback. Readings below 20 are considered oversold. Traders also use the %W in conjunction with volume or momentum indicators to look for divergences — for example, if price makes a new high but %W fails to reach above 80, it may signal weakening bullish momentum. Sustained readings above 50 confirm an uptrend, while sustained readings below 50 confirm a downtrend.

For algorithmic and crypto traders, Bollinger Bands %W is a versatile signal that can be used in both trend-following and mean-reversion strategies. In HaasOnline and similar bot platforms, the %W value can be used as a precise numerical threshold for entering or exiting trades, which is easier to program than interpreting band proximity visually. A mean-reversion bot might buy when %W drops below 10 and sell when it recovers above 50, while a breakout bot might enter long when %W pushes above 100 and hold as long as it stays elevated — both leveraging the same underlying calculation in very different ways.